ATHENS, Greece — It's a goal that has eluded Christianity for nearly 1,000 years: mending the rifts between the Roman Catholic and Orthodox churches. Pope Benedict XVI has already declared a "fundamental commitment" to heal the divide and this week will engage in an indirect round of talks with the Russian Orthodox.
In spiritual terms, it's an epic invitation to repair the broken foundation of the faith — at a time when the European Union is erasing the last Cold War separations and some Christian leaders appeal for greater cooperation to challenge the rise of militant Islam.
But then comes a reality check. Even the smallest steps toward reconciliation can kick up disputes that require the finesse of a diplomat and the perspective of a historian to overcome. And, in the end, any serious bids at rapprochement will force the Vatican to confront some core differences such as honoring Orthodoxy's traditions of autonomous leadership and married clergy.
Greek theologian Athanasios Papathanasiou calls it "the pain of brotherly debate."
It's made more acute because the ancient divide reaches beyond religious differences, which are mostly over liturgical points and joint recognition of sacraments. The bigger gulf, clerics and theologians say, is one of conflicting perceptions and priorities.
When Vatican leaders look east, they see a patchwork of Orthodox churches with a shared fellowship in the roots of Christianity. On May 29 in Italy's Adriatic port of Bari, Benedict declared a "fundamental commitment" to advance dialogue with the leaders of the world's 200 million Orthodox and 1.1 billion Catholics.
The Orthodox view of the West, however, is often shaded by historical grievances — both religious and political — and deep suspicion of Vatican motives and power.
"It's not an even equation," said Thomas Groome, director of the Boston College Institute of Religious Education and Pastoral Ministry. "The deeper skepticism to any improved relations resides within Orthodoxy."
No clear vision exists about what type of unity is even possible or desirable.
For the faithful, one important landmark in the future would be a formal pact on mutual recognition of baptism, marriage and other aspects of church life. But that would require the Orthodox to speak in a single voice — something that's nearly impossible at the moment. The Orthodox world is divided among more than a dozen autonomous churches and other congregations, each with different views.
The Vatican, too, could be pushed into some unfamiliar spots.
Closer bonds with married Orthodox clergy don't present a distinct problem. The Vatican's priestly ranks include married Eastern Rite clerics and some Anglican priests who converted to Catholicism. It could, however, put added pressure on the Vatican to reconsider its ban on married clergy.
A bigger challenge is sorting out the main reason for the split 10 centuries ago: the clout of the papacy versus the Orthodox view of equal distribution of power among its churches.
"Can Rome devise a new way of thinking of primacy that does not lead to dominance over any other churches?" said Anton Vrame, director of the Patriarch Athenagoras Orthodox Institute in Berkeley, Calif. "That is the question only Benedict and the Vatican can answer."
It may not be needed for a long time. Church experts from both sides believe any increased collaboration in coming years may be slow and safe — such as possible joint declarations on social issues or sharing resources for aid work and Christian education. A hint of common ground emerged last month in Ukraine, where Catholic and Orthodox leaders put aside their many internal disputes to urge the government to keep Christian-oriented classes in schools.
Last month, the head of Russia's small Catholic community, Archbishop Tadeusz Kondrusiewicz, said the pontiff seeks to join forces with Orthodox to battle "aggressive secularism." Similar dialogue is ongoing with the two churches and the many Protestant denominations.
"Don't expect big things in a short time," said Brother Jeff Gros, a spokesman on interreligious affairs for the U.S. Conference of Catholic Bishops. "If anything, this will be a gradual evolution."
A World Council of Churches conference last month outside Athens — bringing together clerics and scholars from nearly every Christian denomination — demonstrated the sensitivities.
The head of the Greek Orthodox church, Archbishop Christodoulos, welcomed more than 700 delegates with a call for greater contacts among Christians. But he added some direct swipes against the West — a point-by-point litany of past and present wounds felt by most Orthodox.
They go back to the Crusades, including the 1204 sacking of Constantinople, the ancient center of Greek Byzantium and now — as mostly Muslim Istanbul, Turkey — still the spiritual center of Orthodoxy. Christodoulos zeroed in on the main contemporary obstacle: the growing Eastern Rite churches that follow most Orthodox traditions but are loyal to the Vatican.
Many Orthodox see these churches as Roman Catholic encroachment and attempts to poach followers. Hard-line Orthodox go further. To them, all non-Orthodox Christians are heretics.
"Repent!" a small group of Orthodox zealots shouted through bullhorns outside the conference.
Rifts between the two ancient branches of Christianity began as early as the fifth century over the rising influence of the papacy and later over wording of the creed, or confession of faith. The split was sealed in 1054 with an exchange of anathemas — or damnations — between the Holy See and the patriarch of Constantinople. Centuries of cultural separation deepened the estrangement, and the Protestant Reformation in the 16th century further fragmented Christianity.
Pope John Paul II turned his attention to the Orthodox world late in his nearly 27-year papacy. He traveled to several predominantly Orthodox nations and built close ties with Ecumenical Patriarch Bartholomew I, the "first among equals" among Orthodox leaders. In Greece in 2001, John Paul apologized for "sins of action and omission" by Catholics against Orthodox.
The mutual outreach wasn't enough to win over one of the most powerful figures in Orthodoxy, the ailing Russian Patriarch Alexy II. He refused to allow a papal trip to the world's most populous Orthodox nation. Benedict appears content to move slowly on any proposals to visit Russia, but one of his first meetings as pontiff in April was with the Russian church's top foreign affairs envoy.
This month offers another chance for high-level messages.
On June 16, the general secretary of the World Council of Churches, the Rev. Samuel Kobia, is scheduled to visit Benedict at the Vatican. Kobia then heads for talks with the Russian Church leaders from June 18-24.
The Geneva-based group includes the Orthodox churches. The Vatican is not a full member, but participates on many levels. The pope — then German Cardinal Joseph Ratzinger — served on a WCC panel in the 1970s.
Meanwhile, a joint commission is expected to be formed by next year to "set out an agenda" on improving relations, said the Rev. Brian Farrell, a member of the Vatican's Pontifical Council for Promoting Christian Unity.
The council president, Cardinal Walter Kasper, also urged a pan-Christian synod — Catholics, Orthodox and Protestants — to "form an alliance to rediscover the Christian roots of Europe."
Among the Orthodox, Russia is the heavyweight. But it's not the only voice. Smaller Orthodox churches have power to shape the dialogue. At least one, the Macedonian Orthodox Church leader, believes it's "still too early" to talk seriously of moving closer.
"There are too many differences from the past which cannot be easily resolved," said Archbishop Timotej. "It would be very difficult to ensure a full reconciliation. This is more the pope's good will (gesture) than reality."